The political scientist Kenneth Waltz, who is known, among other things, for his view that nuclear proliferation is a good thing, recently weighed in on the subject of Iran. Writing in the pages of USA Today in advance of an article in Foreign Affairs, Waltz argues that, "a nuclear-armed Iran would probably be the best possible result of the standoff and the one most likely to restore stability to the Middle East."

Waltz writes that diplomacy and sanctions are unlikely to convince Tehran to abandon its quest for nuclear weapons, concluding that, "a country bent on acquiring nuclear weapons can rarely be dissuaded." He similarly dismisses the possibility that Iran could stop short of producing nuclear weapons, arguing that leaders in Tehran would see a "bomb in the basement" as an insufficient deterrent to Israel. Rather, he believes the most likely future as one in which Iran overtly acquires a nuclear weapon.

Such a diagnosis is hardly unique. What is likely to grab attention is his prescription. He argues that Iranian nuclear weapons would be a good thing for the stability of the Middle East. In his words, "policymakers and citizens worldwide should take comfort from the fact that where nuclear capabilities have emerged, so, too, has stability. When it comes to nuclear weapons, now as ever, more could be better."

Waltz is a serious scholar, and his argument deserves serious attention, even if his embrace of nuclear weapons is the sort of thing that makes policy-makers doubt the value of the academy in policy debates.

As befits an international relations theorist, his arguments about the prospects and consequences of proliferation are categorical. Sweeping statements are fine when it comes to theory, but Waltz’s assertions regarding proliferation all too often collide with the facts.

In fact, as Waltz concedes later in the piece, the spread of nuclear weapons is hardly inevitable. Over the last seventy years, a number of countries — including Argentina, Brazil, Sweden, South Korea and Taiwan — launched nuclear weapons programs only to abandon them because of foreign pressure and domestic political change. South Africa fielded a nuclear arsenal only to give it up for similar reasons. Most recently, Muammar Qaddafi gave up Libya’s nuclear program in response to a series of carrots and sticks. And contrary to the arguments of some, governments have used force to interdict a country’s nuclear ambition, including Israel’s 1981 attack on Iraq’s Osirak reactor and its 2007 attack on Syria’s Al Kibar reactor. As Sarah Kreps and Matthew Fuhrmann show in an article in The Journal of Strategic Studies last year, peacetime attacks on nuclear facilities can delay proliferation, particularly when launched well before the nuclear threat is imminent. Such attacks are, however, the least legitimate under international law and are thus most likely to elicit censure.

If Waltz’s fatalism regarding the acquisition of nuclear weapons is misplaced, then so too is his optimism regarding the impact of nuclear possession on state behavior. Not all states are alike. Nuclear weapons in the hands of North Korea or Iran are of far greater concern than those in the hands of Israel or India. Nor would all would agree with his assertion that "fears of proliferation have proved to be unfounded." The world is a more, not less, dangerous place because of North Korea’s possession of nuclear weapons, and it would be an even more dangerous place should Tehran get the bomb.